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Biomedical subjects

G M Hall

Publications and source records attributed to G M Hall.

At least 73 records · Page 4Linked to original sources

Is patient-controlled analgesia controlled by the patient?

Using patient-controlled analgesia (PCA) after surgery, a patient can obtain pain-relieving injections of morphine without the direct involvement of a nurse or doctor. The present study was a response to the conventional view that patients value PCA because of the control which it affords them over their own treatment. Twenty-six patients underwent semi-structured interviews postoperatively, shortly after discontinuation of PCA. Responses were examined qualitatively to identify recurring themes in patients' experience of PCA. Negative as well as positive evaluation was found. PCA was only rarely described as a way of gaining control over analgesia and, in general, this was not valued. Instead, PCA was valued as a way to avoid the difficulty of disclosing pain or securing pain relief within the usual nurse-patient relationship. In turn, PCA strained the nurse-patient relationship where it impeded either the patient's or the nurse's wish for the nurse to take responsibility for pain relief. The results showed that the professionally and theoretically constructed concept of PCA as a method of self-control over pain is inconsistent with patients' experience of it.

Adult↗

Metabolic and hormonal responses to induced hypotension for middle ear surgery.

We have investigated in 30 patients the metabolic and hormonal responses to middle ear surgery using induced hypotension to a mean arterial pressure of 55 mm Hg. A standardized anaesthetic technique of propranolol, thiopentone-vecuronium-isoflurane was used in all patients and hypotension induced with sodium nitroprusside, trimetaphan camsylate or additional isoflurane. All patients showed a classic stress response with an increase in circulating blood glucose, cortisol and growth hormone concentrations. Blood lactate and plasma uric acid concentrations changed little during operation, suggesting that tissue oxygenation was adequate. However, the former declined after operation, possibly as a result of the concomitant use of propranolol. There were no significant differences between the three hypotensive techniques in their effects on the hormonal and metabolic response, although the increase in blood glucose concentration in the trimetaphan group was obtunded. We conclude that induced hypotension for middle ear surgery induced an endocrine and metabolic response of small magnitude and short duration.

Adult↗

A randomized trial of testosterone therapy in males with rheumatoid arthritis.

Thirty-five male patients, aged 34-79 yr, with definite rheumatoid arthritis (RA) were recruited from out-patient clinics and randomized to receive monthly injections of testosterone enanthate 250 mg or placebo as an adjunct therapy for 9 months. Endpoints included disease activity parameters and bone mineral density (BMD). At baseline, there were negative correlations between the ESR and serum testosterone (r = -0.42, P < 0.01) and BMD (hip, r = -0.65, P < 0.01). A total of 29.6% of all patients had at least one vertebral fracture, most having multiple fractures. Back pain, however, was not more prevalent in fracture patients (55% vs 50%). Disease activity was significantly higher in the fracture group (joint score P < 0.05, rheumatoid factor P < 0.01). Thirty patients completed the trial, 15 receiving testosterone and 15 receiving placebo. There were significant rises in serum testosterone, dihydrotestosterone and oestradiol in the treatment group. There was no significant effect of treatment on disease activity overall, five patients receiving testosterone underwent a "flare'. Differences in mean BMD following testosterone or placebo were non-significant (spine: +1.2% vs -1.1%; femur: -0.3% vs +0.3%). There was no suggestion of a positive effect of testosterone on disease activity in men with RA.

Adult↗

Postoperative morbidity following cataract surgery. A comparison of local and general anaesthesia.

Two hundred and thirty-one patients were questioned the day following their cataract surgery to ascertain the incidence of postoperative morbidity. One hundred and nineteen patients received local anaesthesia (LA) and 112 received general anaesthesia (GA). There was a significant difference in the incidence of nausea (21% in GA group, 3% in LA group, p < 0.01), sore throat (41% GA group, 3% LA group, p < 0.01), and bruising of the eye (15% GA group, 39% LA group, p < 0.01). There was no significant difference in the incidence of vomiting, headache, double vision, the severity of postoperative pain, or the need for analgesia. The time before the patients drank and ate postoperatively was significantly shorter in the local anaesthetic group (1.3 h and 1.8 h LA group, 4.1 h and 6.7 h GA group respectively, p < 0.01).

Aged↗

Patients' experiences of patient-controlled analgesia.

We examined patients' experiences of patient-controlled analgesia by the use of semistructured interviews in 26 patients shortly after discontinuation of the device. The options expressed by the patients were examined qualitatively to identify recurring themes in their experience of patient-controlled analgesia. The areas of interest were analgesia, factors influencing whether the patient pressed the button or not, whether they felt in control and side effects. Negative as well as the expected positive evaluations were found. The negative evaluations reflected problems with nausea and vomiting and inadequate analgesia. No clear strategy for pressing, or not pressing, the button emerged and the principle of control by the patient over their pain relief was not considered important.

Adult↗

Markers of bone metabolism in postmenopausal women with rheumatoid arthritis. Effects of corticosteroids and hormone replacement therapy.

OBJECTIVE: To investigate bone metabolism in postmenopausal women with rheumatoid arthritis (RA) treated with or not treated with corticosteroids, and the response to hormone replacement therapy (HRT). METHODS: One hundred six RA patients were divided into those taking low-dose steroids (RA+; n = 35) and those not (RA-; n = 71) and randomly allocated to receive HRT or calcium for 2 years. Bone formation markers included serum osteocalcin (OC) and bone-specific alkaline phosphatase, and resorption markers included urinary deoxypyridinoline (DPyr) and CrossLaps (XL). Bone mineral density (BMD) was measured annually using dual x-ray absorptiometry. RESULTS: OC levels were significantly lower in both the RA+ and RA- groups compared with 112 healthy control subjects (P < 0.01 and P < 0.05, respectively), but were similar in the 2 RA groups. DPyr and XL levels were elevated in the RA+ group compared with the RA- group (P < 0.05) but were similar between the RA- group and controls. OC was negatively correlated with parameters of disease activity (P < 0.05). After HRT, XL excretion decreased significantly in the overall RA group. Three-month changes in XL correlated with 2-year changes in spinal BMD (P < 0.01). CONCLUSION: Bone metabolism may be uncoupled in chronic RA. Bone formation appears to be reduced, partly reflecting disease activity, whereas resorption is increased only in steroid users. HRT reduces resorption in RA irrespective of steroid usage, emphasizing its value in the treatment of postmenopausal women with RA.

Absorptiometry, Photon↗

Metabolic control of non-insulin-dependent diabetic patients undergoing cataract surgery: comparison of local and general anaesthesia.

We studied 40 elderly patients undergoing cataract surgery. Ten non-insulin-dependent diabetes mellitus (NIDDM) patients received standardized general anaesthesia, 10 NIDDM patients received local anaesthesia using retrobulbar block, 10 non-diabetic control patients received general anaesthesia and 10 non-diabetic controls received retrobulbar block. We measured sequential changes in blood glucose, lactate and beta-hydroxybutyrate, serum cortisol and insulin, and plasma non-esterified fatty acid concentrations until 4 h after operation. The results showed that in both general anaesthesia groups, NIDDM and control, blood glucose and serum cortisol concentrations increased significantly during surgery, before returning to normal by 4 h after operation; in both local anaesthesia groups, glucose and cortisol concentrations changed little during surgery. Serum insulin concentrations increased 30 min after operation to coincide with the peak of the glucose increase in the non-diabetic patients who received general anaesthesia, but no insulin response was seen in the diabetic general anaesthesia patients. Blood glucose and insulin concentrations increased in patients who received local anaesthesia (NIDDM and controls) when they ate after operation. The results show that cataract surgery under local anaesthesia provides improved metabolic control for the diabetic patient. Its use maintains glucose homeostasis, prevents the increases in cortisol and glucose which are seen under general anaesthesia and obviates the need for postoperative starvation.

Aged↗

Hormonal effects of thoracic extradural analgesia for cardiac surgery.

We have investigated the hormonal and metabolic effects of thoracic extradural analgesia with bupivacaine in addition to sufentanil 20 micrograms kg-1 in nine patients undergoing coronary artery bypass surgery. A control group received general anaesthesia alone. The catecholamine response was inhibited for 24 h after surgery in patients who had received extradural analgesia, and the cortisol response was suppressed during cardiopulmonary bypass. Blood glucose values were unchanged until 24 h after surgery in the extradural group. There were no significant differences in cardiac index between the two groups of patients, although heart rate and mean arterial pressure decreased before surgery in patients who received extradural analgesia. The benefits of this technique in terms of a reduction in postoperative morbidity remain to be determined.

Adult↗

The effects of differing concentrations of bupivacaine on the epidural somatosensory evoked potential after posterior tibial nerve stimulation.

The somatosensory evoked potential (SEP) recorded from the cervical epidural space in response to stimulation of the posterior tibial nerve is often used to monitor spinal cord integrity during scoliosis surgery. Epidural analgesia may be used as part of the anesthetic technique for scoliosis surgery, but the effects of the local analgesic on the evoked potential must be determined to ensure that it does not interfere with the monitoring of spinal cord function. Therefore, we compared the effects of the administration of 10 mL of 0.25% (n = 8), 0.5% (n = 8), or 0.75% (n = 8) bupivacaine injected into the L3-4 epidural space on the somatosensory evoked potential to posterior tibial nerve stimulation in patients anesthetized with a propofol infusion, nitrous oxide and oxygen, immediately before scoliosis surgery. Compared with a control group (n = 8), a concentration-dependent effect of bupivacaine was found on overall amplitude of the evoked potentials and the amplitude of all peaks. There were no significant differences between 0.25% bupivacaine and the control group, but both 0.5% and 0.75% bupivacaine were associated with clinically and statistically significant decreases in overall amplitude (P < 0.002, 0.5% bupivacaine; P < 0.001, 0.75% bupivacaine). Latency increased similarly in all groups. We conclude that bupivacaine in concentrations greater than 0.25% is not suitable for scoliosis surgery, if spinal somatosensory evoked potentials (SSEP) are to be measured.

Adolescent↗

Effect of hormone replacement therapy on bone mass in rheumatoid arthritis patients treated with and without steroids.

OBJECTIVE: To assess the effect of hormone replacement therapy (HRT) on bone mass in rheumatoid arthritis (RA) patients treated with and those not treated with steroids. METHODS: Two hundred postmenopausal women with RA (ages 45-65 years) were randomly allocated to receive transdermal estradiol (hormone replacement therapy; HRT) (50 micrograms daily) or calcium supplementation (400 mg daily) for 2 years. Forty-two of the patients (21%) were taking corticosteroids. Bone mineral density of the lumbar spine (BMDLS) and of the proximal femur (BMDF) was measured at study entry and at 12 months and 24 months. RESULTS: In the HRT group overall, mean BMDLS had changed by +2.22% (95% confidence interval [95% CI] +0.72, +3.72) and mean BMDF by -0.41% (95% CI -1.89, +1.07) after 24 months. In the calcium group, mean BMDLS changed by -1.19% (95% CI -2.29, -0.09) and mean BMDF by -0.56% (95% CI -2.60, +1.48). Differences between treatment groups were significant for the spine only (P < 0.001). In the 21 HRT-treated patients taking steroids, BMDLS increased by 3.75% (95% CI +0.72, +6.78) and BMDF by 1.62% (95% CI -1.27, +4.51). CONCLUSION: This study shows that HRT increases spinal BMD and maintains femoral BMD in postmenopausal RA. HRT is also an effective agent in preserving bone mass in patients taking low-dose corticosteroids.

Adrenal Cortex Hormones↗

Retrobulbar block fails to prevent an increase in serum cortisol concentration on emergence from anaesthesia after cataract surgery.

We have studied 30 elderly patients undergoing cataract surgery, allocated randomly to receive general anesthesia, local anaesthesia by retrobulbar block or general anaesthesia combined with retrobulbar block given after induction. Retrobulbar block alone prevented the increases in circulating cortisol and glucose values which occurred in those patients receiving general anaesthesia alone. Retrobulbar block given after induction of general anaesthesia, however, suppressed the cortisol and glucose response during surgery, but did not prevent a marked increase in cortisol concentrations during the immediate postoperative period. The results suggest a hormonal response to emergence from anaesthesia which has hitherto been masked by the stress response to surgery itself.

Aged↗

Effects of extradural anaesthesia on interleukin-6 and acute phase response to surgery.

Serum concentrations of the cytokine, interleukin-6 (IL-6), increase after surgical trauma. IL-6 mediates the synthesis of acute phase proteins and stimulates secretion of pituitary hormones. We have examined the time course of circulating IL-6, and cortisol and growth hormone responses in patients undergoing hysterectomy to determine if IL-6 contributes to the early pituitary hormone changes found during surgery. One group (n = 8) received a standardized general anaesthetic while the remaining patients (n = 8) received extradural analgesia to T4-S5 in addition to a similar general anaesthetic. In the general anaesthesia group, there was a significant increase in serum cortisol and growth hormone concentrations before any changes in IL-6 were detected. Furthermore, in the extradural group, in whom these hormonal responses were attenuated, circulating IL-6 concentrations did not differ significantly from the general anaesthesia group. There were no significant differences between the groups in the acute phase response, as measured by circulating concentrations of C-reactive protein and zinc, but the expected effects of extradural block on circulating metabolites and white cell count were demonstrated. We conclude that IL-6 is unlikely to contribute to the initial increases in secretion of pituitary hormones found during surgery, but a later effect of the cytokine on endocrine responses cannot be excluded.

Acute-Phase Proteins↗

Etidocaine and extradural somatosensory evoked potentials after posterior tibial nerve stimulation.

We have examined the effects of lumbar extradural administration of 1% etidocaine 10 ml on somatosensory evoked potentials to posterior tibial nerve stimulation measured in the cervical extradural space. Eight patients, anaesthetized with propofol and nitrous oxide, were studied before hysterectomy and a control group received a similar anaesthetic and 0.9% sodium chloride solution 10 ml in the lumbar extradural space. Etidocaine decreased significantly overall amplitude of the evoked potentials and the amplitudes of all peaks, between 30 and 50 min after extradural injection. The effects of etidocaine on spinal cord conduction were greater than those found previously for lignocaine and bupivacaine, suggesting that it is the local analgesic of choice for inhibiting afferent conduction.

Adult↗

Circulating fluoride changes and hepatorenal function following sevoflurane anaesthesia.

Sevoflurane, a new volatile inhalational agent, undergoes biotransformation to fluoride which is potentially nephrotoxic. We compared the effects of sevoflurane or isoflurane anaesthesia on hepatorenal function and serum fluoride concentrations in 50 ASA 1-3 patients undergoing major intra-abdominal surgery. No patient developed renal or hepatic dysfunction. Mean (SEM) peak fluoride concentrations were 23.1 (1.5) mumol.l-1 for sevoflurane and 5.4 (0.4) mumol.l-1 for isoflurane (p < 0.001). There was a significant correlation in the sevoflurane group between the total dose of agent (MAC h), the total fluoride production (r = 0.78, p = 0.0001) and peak fluoride concentration (r = 0.57, p = 0.003). There was no correlation between these variables in the isoflurane group.

Adult↗

Sevoflurane anaesthesia for major intra-abdominal surgery.

The cardiovascular effects and recovery characteristics of sevoflurane and isoflurane anaesthesia were compared in 30 gynaecological and 20 general surgical patients undergoing elective intra-abdominal surgery. Patients were randomly allocated to receive either sevoflurane or isoflurane as the volatile agent, in a balanced anaesthetic technique including morphine and atropine premedication and thiopentone, fentanyl, vecuronium and nitrous oxide. The concentration of volatile agent was titrated according to clinical variables. Mean heart rate, systolic and diastolic arterial pressure and duration of surgery did not differ between the two groups. Time to emergence from anaesthesia in the gynaecological patients was significantly faster after sevoflurane compared with isoflurane (p < 0.005). Sevoflurane provided stable anaesthesia during major intra-abdominal surgery.

Abdomen↗